#include<iostream>
#include<vector>
#include<algorithm>
using namespace std;

class Solution {
public:
    int search(vector<int>& nums, int target) {
        int left = 0, right = nums.size() - 1;
        while(left <= right){
            int mid = (left + right) / 2;
            if(nums[mid] > target){
                right = mid - 1;
            }else if(nums[mid] < target){
                left = mid + 1;
            }else{
                return mid;
            }
        }
        return -1;
    }
};

int main()
{
    Solution s;
    vector<int> nums = {-1,0,3,5,9,12};
    int target = 9;
    cout << s.search(nums, target) << endl;
    return 0; 
}